Lifting-jack.



No. 690,28l. Patented Dec. 3|, |90l. L. o. HENGGI. LIFTING JACK.

(Application led July 2, 1901.)

2 Sheets-Sheet ll.

(N0 Model.)

40: azzyf.

INVENTOR @a Jfy WITNESSES No. '6940,28l. Patentd Dec. 3|, |90I', L. 0. HENGGI.

LIFTING JACK.

(Application filed July 2, 1901.) (l0 Model.) 2 Sheets-Sheet 2.

WITNESSES INVENTOR Zing' f' UNITED STATES PATENT OFFICE.

LEWIS O. IIENGGI, OF VERONA, PENNSYLVANIA.

' LIFTING-JACK.

SPECIFATION forming part 0f LQEIS Patent NO. 690,281, dated Deeln'bel 31, 1901. Y Application filed July 2,1901. Serial No. 56,895. (No model.) A

To @ZZ whom, timmy concern,.-

Be it known that I, LEWIS O. HENGGI, of Verona, Allegheny county, Pennsylvania, have invented a new and useful Jack, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a side elevation of my improved jack. Fig. 2 is a vertical section on the line I-I II of Fig. 1. Fig. 3 is a view similar to Fig. 1, taken on the opposite side and with parts broken away. Fig. 4 is a side elevation, partly broken away, showing the parts in position for lowering. 'Fig 5 is a side elevation, partly broken away, on the opposite side to that of Fig. 4; and Fig. 6 is a side view similar to Fig. 4 with the parts in a different position.

My invention relates to that class of jacks which are arranged to be moved either up or down with step-by-step movement; and its object is to do away with the use of springs heretofore commonly employed in connection with the devices for changing the pawls from their position in moving the liftingbarlupwardly to that in moving down; and to that end it consists in arranging swinging weights in such a manner that they will act upon the pawls to reverse the movement of the jack.V

In the drawings, 2 representsthe hollow standard. or casing of the jack, and 3 the toothed lifting-bar vertically guided therein.

4 is the operating-lever, pivoted at 5 to the hollow standard and having pawl 6 pivoted to its inner end. The casing-pawl 7 `is shown as in U form, surrounding the lifting-bar and pivoted to the casing, as shown at 8.

The parts above described are old in this class of jacks, and I will now describe the novel mechanism by which the action of the jack is reversed. A crank-shaft 9 is mounted in a proper' bearing in the lower pawl, this shaft having at its opposite ends oppositelyextending crankarms 10 and 11. To the crank-arm 10 is pivoted a weight 12, having an upper nose portion 13, arranged to contact with the inclined lower end face 14 of the upper pawl. The other crank-arm 11 is provided with a weight 15 of the general formA shown in Fig. l, it having acurved recessed portion 16, which in certain positions engages i i a pin 17 on the inside of the casing. The

crank-arm 1l is provided with a pin or turnbutton 18, which projects through a hole in theside of the casing and by which the crank or eccentric shaft may be turned either into the position shown in Fig. 1 or that shown in Fig. 4. The shaft is retained in either position by means of a spring-latch 19, which engages suitable recesses therefor cut in the shaft, a slot being cut away in the central part of the pawl to receive the latch.

In the operation of the jack in raising the lifting-bar step by step the parts are in the position shown in Figs. 1 to 3, inclusive, and as the operating-lever is lowered the lower pawl forces the lifting-bar upwardly, while t-he upper pawl is forced out by the inclined face of the tooth and drops into the next tooth. On again lifting the lever the lower pawl moves into its original position one tooth lower down.- When the lifting-bar is to be lowered step by step, the crank or eccentric shaft is turned ninety degrees by means of the turn-button 18. The weight 12 is thus thrown out into position where it will engage the in clined lower face 14 of the upper pawl, while the weight 15 will be acted upon by the casingpin. In this position of theparts on lifting V the lever the pin will force out the lower pawl and then allow it to move into the next tooth above. Now on moving down the lever the nose 13 ofthe weight 12 acting upon the inclined face 14 of the upper pawl forces it back, as shown in dotted lines in Figs. 4 and 5, into position where it will engage the next higher tooth as the lever is lifted. These movements thus reverse the movement of the liftingbar and allow it to move down step by step.

The advantages of myinvention result from the doing away with all springs and the reversal of the pawl action by means of swinging weights which may be thrown into operative or inoperative position.

Many variations may be made in the form and arrangement of the pawls, their points of support, the lifting-bar, and the other parts without departing from my invention.

I claim- 1. A jack having a toothed lifting-bar, and two pawls engaging the same, a pivoted weight arranged to swing during the step-by-stcp lowering vand act upon the pawls, and mechanism forchanging'the position of the Weight to reverse the step-by-stepimovement; substantially as described.

2. A jack having a toothed lifting-bar, two pawls engaging the teeth on the same side of the bar, swinging cams or weights pivoted to one pawl, and mechanism for changing the 'tion ofthe Weights; substantially as described.

5. A `jack having two pawls lin vertical alinement, the lower -pawl having-an eccentric crank-shaft mounted therein, Weighted cams pivoted eccentrically to said shaft, one of said .Weights engaging `the upper pawl, While the other engages a projection on the casing, and mechanism for turning the shaft and holding it in adjusted position; substantially as described.

6. A lifting-jack having a lifting-bar with teeth on one side, an upper pawl pivoted to the 4.frame and engaging the teeth, an operating-lever mounted in the frame, a pawl pivoted to the lever and also engaging the teeth, an eccentric or crankshaft pivoted to the lower pawl and having a cam device arranged to act upon `the upper paw), and another cani device arranged to coact with the projection on the casing, the position of the cam devices being changed by turning the shaft to reverse the-step-bystep movement of the lifting-bar; substantially as described.

Intestirnony whereof I have 'hereunto set my hand.

LEWIS O. HENGGI. 

